Ratchet arrangement for an explosion driven setting gun

ABSTRACT

In an explosion driven setting gun using a detachable protective cap on the forward end of the gun housing, the cap is secured against rotation by a radially displaceable ratchet mounted in the housing. The ratchet is also axially displaceable so that it can be removed from locking engagement with the trailing end of the protective cap. Two springs act on the ratchet, one biasing it radially inwardly and the other biasing it axially into engagement with the protective cap. For releasing the ratchet from engagement with the protective cap, the gun housing has an opening aligned opposite the ratchet so that a member can be inserted through the opening into a notch in the ratchet for displacing it axially against the axial spring biasing action.

United States Patent 1191 ()esterle et al.

RATCHET ARRANGEMENT FOR AN EXPLOSION DRIVEN SETTING GUN Inventors: Helmut Oesterle, Nofels; Fritz Mark, Mader; Peter Jochum, Meiningen, all of Austria Hilti Aktiengesellschaft, Fuerstentism, Liechtenstein Filed: June 4, 1973 Appl. No.: 366,579

Assignee:

Foreign Application Priority Data June 7, 1972 Germany 2227774 References Cited UNITED STATES PATENTS 12/1956 Broughton et al. 227/ll 2/1960 Kuavle 227/8 2/1960 Kopf et al. 227/8 11] 3,827,618 1451 Aug. 6, 1974 3,283,983 11/1966 Neighorn et al. 227/11 3,610,504 10/1971 Oesterle 227/8 Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, or FirmToren, McGeady and Stanger [5 7] ABSTRACT In an explosion driven setting gun using a detachable protective cap on the forward end of the gun housing, the cap is secured against rotation by a radially displaceable ratchet mounted in the housing. The ratchet is also axially displaceable so that it can be removed from locking engagement with the trailing end of the protective cap. Two springs act on the ratchet, one biasing it radially inwardly and the other biasing it axially into engagement with the protective cap. For releasing the'ratchet from engagement with the protective cap, the gun housing has an opening aligned opposite the ratchet so that a member can be inserted through the opening into a notch in the ratchet for displacing it axially against the axial spring biasing action.

7 Claims, 2 Drawing Figures All SUMMARY OF THE INVENTION The present invention is directed to an explosion driven setting gun for driving fastening elements into a target material and, more particularly, it concerns a a ratchet arrangement for detachably securing a protective cap on the forward end of the housing of the setting gun.

Explosion driven setting guns are known which include a barrel mounted for axial displacement within the gun housing and with a protective cap detachably connected to the forward end of the housing'To secure the protective cap against displacement when in use, a ratchet is located within the housing and is loaded by a spring inwardly toward the barrel. The ratchet has an inwardly extending detent for engagement within an annular groove in the barrel so that the barrel cannot be moved into the firing position when the protective cap is removed. With the protective cap on the housing, the detent is displaced from the groove in the barrel and the radial displacement path of the ratchet is limited by the protective cap. Further,the cap contains at least one locking groove into which the ratchet can engage for preventing accidental disengagement of the cap from the housing.

Fastening element setting guns used for higher outputs must be equipped with protective caps for safety reasons. These protective caps protect the operator of the setting gun from any parts of the target material which are broken off during the fastening element driving operation.

Accordingly, such setting guns have so-called protective cap safety devices, that is, safety devices which prevent operation of the setting gun when the protective cap is detached. In such setting guns it has been known to use an axially displaceable barrel which is resiliently biased in the driving direction by a spring member. A radially displaceable ratchet is located within the housing and is spring biased inwardly toward the barrel. The ratchet has an inwardly directed detent for engagement with a groove on the barrel. The safety cap is detachably secured to the housing by means of a bayonet lock. To prevent accidental release of the bayonet lock between the protective cap and the housing, the ratchet engages a locking groove formed on the cap.

In such known setting guns, when the protective cap is removed from the housing, the ratchet is displaced inwardly by the action of the spring so that its detent moves inwardly until it rests on the surface of the barrel. Since the barrel is displaced in the driving direction by a spring force when it is in the rest position, the annular groove in the barrel moves forwardly into the range of the detent on the ratchet and the detent seats within the groove when the cap is removed. As a result, it is not possible to push the barrel rearwardly into the operating or firing position without disengaging the detent from the groove, such disengagement is effected when the protective cap is attached to the setting gun housing.

In this known safety device two different operating functions are performed by the radial displacement of the ratchet, that is, on one hand, the engagement of the detect within the annular groove on the barrel prevents the return movement of the barrel into the firing position and, on the other hand, the engagement of the ratchet in a locking groove on the protective cap secures the cap against rotation relative to the gun housing. Because of this double function of the ratchet, it is impossible to provide a stop which limits the radial displacement of the ratchet after the detent has been disengaged from the annular groove in the barrel. A rather considerable radial movement of the ratchet is required for the engagement and disengagement of the locking groove in the protective cap. This radial movement of the ratchet in conventional setting guns has the disadvantage that the ratchet is directed radially outwardly by the vibrations developed during the firing of the gun with the result that the ratchet is disengaged from the grooves in the protective cap so that the locking action is released and the protective cap becomes separated from the housing. Such accidental displacement of the protective cap makes the handling of the gun particularly difficult and, in addition, it has adverse effects on the gun itself, since the gun experiences premature v wear and damages.

Therefore, it is the primary object of the present invention to provide a fastening element setting gun in which the above disadvantages are overcome while assuring that the protective cap is securely held on the housing of the gun.

In accordance with the present invention, the locking groove or grooves forthe protective cap are arranged on its trailing end, that is, the end of the cap facing oppositely to the firing direction, and the ratchet within the housing is mounted for axial displacement and is spring loaded for engagement within the locking grooves of the cap.

in such an arrangement, the movement of the ratchet is, so to speak, divided into two components with each component of movement having a special function. Accordingly, the radial movement of the detent on the ratchet effects the engagement and disengagement of the ratchet with the annular groove on the barrel, while the axial movement of the ratchet affords the engagement and disengagement with the locking grooves formed in the trailing end of the protective cap, and the engagement of the ratchet within the grooves prevents rotation of the cap. By this subdivision of the operating functions of the ratchet into directional components, there is the advantage that the setting gun housing can be arranged as a closed member surrounding the ratchet so that a limit against axial radial yielding of the ratchet is afforded. Completely independent of the engagement and disengagement of the detent within the annular groove in the barrel, the ratchet is biased in the axial direction by a spring element, preferably a compression spring, into the locking groove in the protective cap. With the ratchet held by the spring action within the locking groove, accidental disengagement of the ratchet is prevented and the protective cap cannot be inadvertently separated from the gun housing.

When the protective cap is to be removed from the housing, for example, for cleaning purposes, the ratchet must be disengaged from the locking grooves in the axial direction by a force acting oppositely to the force of the biasing spring. To afford access to the ratchet, it is preferable to provide an opening in the gun housing in the range of the ratchet.

For simple disengagement of the ratchet, a pointed object is inserted through the opening in the housing into a notch preferably provided in the ratchet aligned opposite the opening so that the ratchet can be displaced against the force of its biasing spring.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a side view, partly in section, of a fastening element setting gun, incorporating the present invention, and arranged in the operating or firing position; and

FIG. 2 is a partial sectional view of a portion of the setting gun shown in FIG. 1 with the protective cap removed and the gun withdrawn from the target material.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 a fastening element setting gun I is shown having a housing divided into two parts la, lb. The housing part 1b includes a handle 2 containing a trigger 3 which actuates a firing pin 4. Axially displaceable through both of the housing parts la, lb is a barrel 5 which projects forwardly in the firing direction from the housing part la. At its rear end, the barrel has a cartridge chamber 6 into which cartridges 7 are inserted for firing by the firing pin 4. When a cartridge is fired, the gases released accelerate a piston 8 for movement in the axial direction through barrel 5, so that the piston strikes against a nail 9 inserted into the muzzle or forward end of the barrel 5. The kinetic energy of the piston 8 drives the nail 9 from the barrel into the target material 11.

As can be seen in FIG. 1, a protective cap 12 is disposed laterally about the forward end of the barrel 5 and contacts the target material into which the nail 9 is driven. The protective cap is secured by means of a known bayonet lock on housing part 1a which laterally encloses the front part of the barrel 5 in the operating or firing position of the gun. As known, the protective cap is pushed in the axial direction over housing part 1a and then is rotated by a certain angular amount relative to the housing part 1a so that the cam 12a of the protective cap 12 and the cam 10 of the housing part 1a cooperate in providing the interengagement between the two. To prevent accidental loosening of the protective cap, it is secured against rotation in the attached state by the engagement of a ratchet 13 in a locking groove 12b provided in the rear or trailing end of the protective cap 12. The ratchet 13 is biased into the locking groove 12b by a spring 14. The ratchet 13 and its spring 14 are mounted within the leading or forward end of the housing part 1a.

Further, as illustrated in FIG. 1, in addition to the axial bias acting on the ratchet 13, a radial bias is provided by spring 15 which presses the ratchet radially inwardly toward the outer surface of the barrel. With the protective cap 12 attached to the housing part 1a, the radial component of displacement of the ratchet 13 is limited by the side surface of the protective cap 12 adjacent its trailing end. The radial dimension of detent 13a extending inwardly from the ratchet toward the barrel is such that with the ratchet contacting the side surface of the protective cap the detent does not quite contact the barrel.

If the protective cap 12 is removed from the housing part 1a, for example, for cleaning, the removal is performed by inserting a pointed object through an opening 1d located in the housing part 1a opposite the ratchet and, by means of the pointed object, pushing the ratchet rearwardly against the force of the axially directed spring 14. Preferably, the pointed object engages a notch 13b in the surface of the ratchet for effectively displacing it. With the ratchet displaced axially out of the locking groove 12b in the trailing end of the protective cap, the cap is released and can be removed in a known manner from housing part la. To limit the axial movement of the spring-loaded ratchet 13 at the forward end of the housing part la, a stop 10 is secured on the housing part by means of a screw 18 for retaining the ratchet within the housing when the protective cap 12 is removed. In the setting gun shown in FIG. 1 a so-called pressure lock is provided so that, when the gun 1 is lifted or withdrawn from the receiving material 11, the barrel 5 is forced forwardly in the driving direction by a pin 17 loaded by a spring 16 until a collar 5a on the outer surface of the rearward portion of the barrel contacts a stop on the housing part 1a which extends into the path of the collar. As the barrel moves forwardly it carries the cartridge 7 secured in the cartridge chamber 6 along with it to a position where the cartridge is out of the range of the firing pin 4 so that, even though the firing pin is actuated by the trigger, it cannot strike against the cartridge 7 until the gun is returned to the firing position by pressing the barrel against the target material 11.

During the forward movement of the barrel 5, that is, in the driving direction, the annular groove 5b formed in the outer surface of the barrel 5 moves into the range of the detent 13a on the ratchet 13. With the protective cap 12 in place on the setting gun, the detent is held outwardly from the surface of the barrel, however, when the cap is removed the limitation on the radial component of movement of the ratchet is withdrawn and, due to the action of the spring 15, its detent is forced radially inwardly into contact with the annular groove 5b. In FIG. 2, with the protective cap removed from the setting gun, the detent 13a on the ratchet is shown in engagement within the annular groove 5b of the barrel 5. As a result, with the protective cap removed, the barrel cannot be forced rearwardly toward the firing pin and the cartridge 7 is retained in a position so that it cannot be fired.

When the protective cap is again positioned on the housing part la, its cam 12a effects the disengagement of the detent 13a of the ratchet 13 from the annular groove 5b and, for this purpose, the forward inner edge of the ratchet 13 is provided with a suitable bevel to facilitate the relative movement of the cam 12a and the ratchet 13 so that the detent is withdrawn from the groove. With the protective cap fixed to the forward end of the housing part la, the barrel can move freely rearwardly in the axial direction into the firing position by pressing the forward end of the barrel against the target material.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. Explosion driven setting gun for driving fastening elements, such as bolts, studs and the like, into a target material, comprising a housing, a barrel mounted within said housing for displacement in its axial direction relative to said housing and having its forward end projecting outwardly from said housing, said barrel having an annular groove formed in its outer surface intermediate its ends, a protective cap detachably secured to the end of said housing from which the forward end of said barrel projects, a ratchet mounted within said housing and being radially displaceable relative to said barrel, a spring member arranged to bias said ratchet member radially inwardly toward said barrel, said ratchet includes a detent for engagement in the annular groove in said barrel, said protective cap having at least one locking groove for engaging said ratchet and said protective cap limits the radially inwardly directed movement of said ratchet, wherein the improvement comprises that said protective cap has a leading end arranged to contact the target material and a trailing end facing in the opposite direction and extending laterally around said housing, the locking grooves of said protective cap being located in its trailing end, said ratchet being mounted within said housing for axial movement relative to the locking groove in said protective cap, and a spring element located within said housing and biasing said ratchet in the direction of said protective cap.

2. Explosion driven setting gun, as set forth in claim 1, wherein said spring element is a compression spring.

3. Explosion driven setting gun, as set forthin claim 1, wherein said housing has an opening therethrough in the range of the location of said ratchet for inserting a member through the opening into contact with said ratchet for displacing it axially against the biasing action of said spring element. v

4. Explosion driven setting gun, as set forth in claim 3, wherein said ratchet has a notch formed therein aligned inwardly from the opening in said housing so that the member inserted through the opening in the housing can be engaged in said notch for axially displacing said ratchet.

5. Explosion driven setting gun, as set forth in claim 1, wherein a stop is mounted on said housing at the opposite end of said ratchet from said spring element for limiting the axial movement of said ratchet due to said spring element when said protective cap is detached.

6. Explosion driven setting gun, as set forth in claim 1, wherein said detent on said ratchet extends radially inwardly transversely of the axial direction of said barrel and the radial dimension of said detent is less than the radial dimension between the radially outer side of the trailing end of said protective cap and the outer surface of said barrel so that when said ratchet is in contact with the radially outer side of said protective cap said detent is spaced radially outwardly from the outer surface of said barrel.

7. Explosion driven setting gun, as set forth in claim 1, wherein the radially inner surface of said ratchet at its end facing in the direction of said protective cap is beveled for facilitating disengagement of said detent from the annular groove in said barrel when said protective cap is fitted onto said housing.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,827,618 Dated August 6, 1974 Inventor) Helmut Oesterle et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Heading of the Patent:

The address of inventor Fritz Mark should read:

- M'aider, Austria--.

The address of the assignee should read:

.-- Schaan, Fuerstentum Liechtenstein--.

Signed and sealed this 26th day of November 1974 (SEAL) Attests McCOY M. GIBSON JR. 0. MARSHALL DANN 5 Attesting Officer Commissioner of Patents USCOMM-DC 0057 B-PGO FORM PO-1050 (10-69) I w u.s. covznuneu-r PIIINI'ING omc: nu o-ass-au. 

1. Explosion driven setting gun for driving fastening elements, such as bolts, studs and the like, into a target material, comprising a housing, a barrel mounted within said housing for displacement in its axial direction relative to said housing and having its forward end projecting outwardly from said housing, said barrel having an annular groove formed in its outer surface intermediate its ends, a protective cap detachably secured to the end of said housing from which the forward end of said barrel projects, a ratchet mounted within said housing and being radially displaceable relative to said barrel, a spring member arranged tO bias said ratchet member radially inwardly toward said barrel, said ratchet includes a detent for engagement in the annular groove in said barrel, said protective cap having at least one locking groove for engaging said ratchet and said protective cap limits the radially inwardly directed movement of said ratchet, wherein the improvement comprises that said protective cap has a leading end arranged to contact the target material and a trailing end facing in the opposite direction and extending laterally around said housing, the locking grooves of said protective cap being located in its trailing end, said ratchet being mounted within said housing for axial movement relative to the locking groove in said protective cap, and a spring element located within said housing and biasing said ratchet in the direction of said protective cap.
 2. Explosion driven setting gun, as set forth in claim 1, wherein said spring element is a compression spring.
 3. Explosion driven setting gun, as set forth in claim 1, wherein said housing has an opening therethrough in the range of the location of said ratchet for inserting a member through the opening into contact with said ratchet for displacing it axially against the biasing action of said spring element.
 4. Explosion driven setting gun, as set forth in claim 3, wherein said ratchet has a notch formed therein aligned inwardly from the opening in said housing so that the member inserted through the opening in the housing can be engaged in said notch for axially displacing said ratchet.
 5. Explosion driven setting gun, as set forth in claim 1, wherein a stop is mounted on said housing at the opposite end of said ratchet from said spring element for limiting the axial movement of said ratchet due to said spring element when said protective cap is detached.
 6. Explosion driven setting gun, as set forth in claim 1, wherein said detent on said ratchet extends radially inwardly transversely of the axial direction of said barrel and the radial dimension of said detent is less than the radial dimension between the radially outer side of the trailing end of said protective cap and the outer surface of said barrel so that when said ratchet is in contact with the radially outer side of said protective cap said detent is spaced radially outwardly from the outer surface of said barrel.
 7. Explosion driven setting gun, as set forth in claim 1, wherein the radially inner surface of said ratchet at its end facing in the direction of said protective cap is beveled for facilitating disengagement of said detent from the annular groove in said barrel when said protective cap is fitted onto said housing. 